Sensitivity and Specificity of Magnetic Resonance Cholangiopancreatography against Endoscopic Retrograde Cholangiopancreatography in Diagnosing Choledocholithiasis

Abstract

Background: Various imaging modalities including EUS (Endoscopic ultrasound), CT abdomen (Computed tomography), MRCP (Magnetic resonance cholangiopancreatography), and ERCP (Endoscopic retrograde cholangiopancreatography) are used for diagnosis of choledocholithiasis. ERCP allows direct visualization of bile duct through endoscope, and it also helps in retrieval of stones. On the other hand, MRCP is a noninvasive procedure which uses strong magnetic field to visualize hepatobiliary system. In patients with choledocholithiasis calculi appear as dark filling defects within high signal intensity fluid at MRCP. This study compares the diagnostic accuracy of MRCP in comparison to ERCP in patients with choledocholithiasis. This study aims to compare sensitivity and specificity of MRCP in comparison to ERCP in diagnosing choledocholithiasis.
 Methodology: This comparative cross-sectional study included 170 patients with clinical diagnosis of choledocholithiasis who presented in Liver Center, Holy Family Hospital, Rawalpindi, during the year 2017. Non-probability consecutive sampling technique and a set of established inclusion and exclusion criteria was used to enroll patients. Data was collected by a self-structured questionnaire. Information about the demographic details and findings of ERCP and MRCP were noted on that questionnaire. Data analysis was done using SPSS 25.
 Results: Out of 170 patients, 111 (65.29%) were females and 59 (34.71%) were males. The mean of age for study population was 45.68 with standard deviation (SD) of ±12.40. ERCP confirmed stones in 95 patients while in case of MRCP 87 true positives, 55 true negatives, 20 false positives, and 8 false negatives cases were noted. According to these results, the sensitivity and specificity were 91.6% and 73.3% respectively for MRCP against ERCP. Whereas positive predictive value and negative predictive values were 81.3 and 87.3% respectively for MRCP in comparison to ERCP.
 Conclusion: MRCP has 91.6% sensitivity compared to ERCP. Although MRCP is a comparatively noninvasive procedure, but ERCP remains the diagnostic modality of choice for choledocholithiasis. MRCP could be used in diagnosis of choledocholithiasis instead of ERCP when there are contraindications of ERCP or when no therapeutic role of ERCP is required.
 Recommendations: MRCP should be used when only diagnostic role of ERCP is needed. MRCP should be used when there are contraindications of ERCP. Level of expertise should be increased for MRCP and ERCP.